The Mandart circle is the circumcircle of the extouch triangle. It has center at Kimberling
center 
,
which has trilinear center function
 |
(1)
|
and radius
 |
(2)
|
where 
is the circumradius of the reference
triangle and 
is the semiperimeter.
It has trilinear circle function
 |
(3)
|
which corresponds to Kimberling center 
.
The Mandart circle passes through Kimberling centers 
for 
(the Feuerbach point 
) and 1364, which are its two intersections
with the incircle.
The Mandart circle is also the circumcircle of 
(the isogonal
conjugate of the Bevan point), which is identical
to the Cevian triangle of 
(P. Moses, pers. comm., Dec. 16, 2004).
